Addition of alkynes and osmium carbynes towards functionalized dπ–pπ conjugated systems

Abstract

The metal-carbon triple bonds and carbon-carbon triple bonds are both highly unsaturated bonds. As a result, their reactions tend to afford cycloaddition intermediates or products. Herein, we report a reaction of M≡C and C≡C bonds that affords acyclic addition products. These newly discovered reactions are highly efficient, regio- and stereospecific, with good functional group tolerance, and are robust under air at room temperature. The isotope labeling NMR experiments and theoretical calculations reveal the reaction mechanism. Employing these reactions, functionalized dπ-pπ conjugated systems can be easily constructed and modified. The resulting dπ-pπ conjugated systems were found to be good electron transport layer materials in organic solar cells, with power conversion efficiency up to 16.28% based on the PM6: Y6 non-fullerene system. This work provides a facile, efficient methodology for the preparation of dπ-pπ conjugated systems for use in functional materials.

Nanographene–Osmapentalyne Complexes as a Cathode Interlayer in Organic Solar Cells Enhance Efficiency over 18%

“…We first used the osmapentalyne derivatives as electron transport layers in OSCs in 2020, [ 25 ] and the versatile function of osmapentalyne derivatives still needs deeper research. Graphene and its derivatives possess a unique large π‐conjugated chemical structure with energy levels that can be easily tuned by functionalized chemical modification.…”

“…[ 27 ] The d π – p π conjugated systems of osmapentalynes could be further extended by connecting them with the organic p π – p π systems of HBCs. Accordingly, we designed and synthesized these large d π – p π conjugated systems by using the reported highly efficient and specific addition reactions [ 25 ] of osmapentalynes and alkynes ( Figure a). Solutions of osmapentalyne complexes in dichloromethane were treated with ≈0.5 equivalents of p ‐diethynyl‐hexabenzocoronenes in the presence of excess HCl·Et 2 O under a N 2 atmosphere at room temperature (rt).…”

Film‐Depth‐Dependent Light Reflection Spectroscopy for Photovoltaics and Transistors

“…In order to explore the film‐depth‐dependent reflection and absorption spectroscopy, PM6 (based on 4,8‐bis(5‐(2‐ethylhexyl)‐4‐fluorothiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b]‐dithiophene [BDT‐F] and 1,3‐bis(thiophen‐2‐yl)‐5,7‐bis(2‐ethyl‐hexyl)benzo‐[1,2‐c′:4,5‐c′]dithiophene‐4,8‐dione [BDD]) and Y6 ((2,2′‐((2Z,2′Z‐(12,13‐bis(2‐ethyl‐hexyl)‐3,9‐diundecyl‐12,13‐dihydro‐[1,2,5]thiadiazolo[3,4‐e]thieno[2,3′:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2g]thieno[2′,3′:4,5]thieno[3,2‐b]indole‐2,10‐diyl)bis(methanylylidene))bis(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐indene‐2,1‐diylidene))dimalononitrile), the model electronic donor and acceptor materials for photovoltaic with power conversion efficiency (PCE) over 15%, [ 27–31 ] are selected (Figure 1b). The normalized absorption (solid lines) and reflection (dashed lines) spectra of pure PM6 and Y6 films are plotted in Figure 1c.…”

Silicon Naphthalocyanine Tetraimides: Cathode Interlayer Materials for Highly Efficient Organic Solar Cells

“…However, PFN‐Br can only work efficiently with an extremely thin cathode interlayer (about 5 nm) due to p‐type property of the polyfluorene backbone, and the thickness of several nanometers is difficult to realize in industrial production [15, 16] . Since the confined WF tunability of PDINO, it shows excellent performance in photovoltaic devices mostly with aluminum (Al) electrode which is unstable to water and oxygen [17–19] . It is valuable to develop new high‐performance organic CIMs.…”